LONDON (Reuters) - Britain fined five major banks including UBS (>> UBS AG) and Citigroup (>> Citigroup Inc) 1.1 billion pounds ($1.75 billion) for failings in currency trading in a landmark settlement after a scandal that has roiled the world's largest market.

HSBC (>> HSBC Holdings plc), Royal Bank of Scotland (>> Royal Bank of Scotland Group plc) and JP Morgan (>> JPMorgan Chase & Co.) also settled UK allegations of failures after a year-long probe that has put the largely unregulated $5 trillion-a-day market on a tighter leash with dozens of dealers suspended or fired.

Barclays (>> Barclays PLC) had been expected to be part of the settlement, but the FCA said on Wednesday its investigation into the UK bank was continuing.

Switzerland's UBS took the lion's share of the joint penalty, paying $371 million. U.S. banks Citigroup and JPMorgan were fined $358 million and $352 million respectively and HSBC paid $343 million and RBS $344 million.

Shortly before the FCA release, the Washington-based Commodity Futures Trading Commission (CFTC) regulator said it was fining five banks $1.4 billion for attempted manipulation in the foreign exchange market.

(Reporting by Kirstin Ridley, editing by Huw Jones)